What's fun going on overnight stay at Oedo Onsen Monogatari? Before planning your trip in Odaiba Tokyo, that is must thing to do. Making a note to visit Oedo Onsen Monogatari and spend a night there. Meanwhile,Plan B should be going on for other fun things to do to avoid too much overnight stay cost. 
Oedo Onsen Monogatari: E-ticket Price Fun Guide
Actually, for some tourists, their Plan B is to overnight at a cybercafe but chicken out and stay at a budget hotel instead. The icing on the cake is when you find out that there is an event for your favourite anime/ manga Gintama at Oedo Onsen and that you would be there during the last two days of the event so they choose overnight stay.

Cost-Effective Fun Things to Do

If you ask my answer, staying overnight at Oedo Onsen meant saving one night's stay at a hotel. Since I already want to soak in hot springs, adding on the extra 1700JPY is not too bad, as for price. However, if you are travelling , this might be a more expensive option for accomodation.

Admission OvernightStay

If you are going to spend the rest of night at Oedo Onsen, you can pay for evening entrance past 6pm, 1680JPY instead of day entrance fees from 11am to 6pm. Before heading to the ticket counter, visitors need to put their shoes in shoe lockers. After putting away your shoes, you can go to queue with the rest of the people. Since there is still about 10 min before 6pm, everyone has to wait patiently no matter they are temporarily stay or overnight stay.
About 5 min before 6pm,  a lady dresses in traditional outfit came out with a pair of clappers and say lots of things in a sing-song tone. Tourists remember from their website that she is the kanban-musume Oshino. This literally translates to Signboard girl which means she is the attraction of a business of overnight stay.
Oedo Onsen Monogatari: E-ticket Price Fun Guide